PMDI.
Word Wrap = On.
Open a long file containing long lines. (Tab A)
Split the window into 4 panes.
Let all panes display the end of the document.
Enable another tab.
Enable tab A.
* The positions presented in the panes changed. (No longer at the end of the document.)

* Such behaviors also affect the view when Finding Next Up/Down. The selected match may not be seen in the current pane.

* When split, the bookmarks set in one pane cannot be found in another pane.

* Word-wrap status should be considered when saving the bookmark position.

BTW, a suggestion:
For example, in EmEditor, "Toggle Vertical Split" when the window is already split horizontally. EmEditor will toggle the vertical split without changing the horizontal split.
But AkelPad does such things by first turning off the existing one and then turning on another.
When we work in 2 panes and want to switch to 4 panes, we usually don't want the previously presented positions lost.